NO NO NO NO NO NO!!!!!
Whoever told you that has no regard for the health and well-being of the horse.....glad to see that you are asking for 2nd opinions.....
Personally, the oldest horse I have bred was a 24 year old mare - BUT - she was a proven broodmare, great momma and also in excellent shape. Although I know she throws GREAT foals - that was her last breeding, and is still around at 31 years old.

